The command ":a <expr>" evaluates <expr> and adds the attributes in the resulting attribute set to the interpreter scope. For instance: nix-repl> :a import <nixpkgs> {} nix-repl> lib.range 0 10 [ 0 1 2 3 4 5 6 7 8 9 10 ]
This program interactively reads a Nix expression from the user, evaluates it, and prints the result.